Wednesday, 27 July 2016

Why is our youth, from adolescence to early adulthood, so ripe with memories compared with other times in life? Research has firmly established this "reminiscence bump", with various explanatory theories: it contains many unforgettable first times; the young mind is sharper; and we reflect on these early events to reinforce our sense of identity. The trouble is, it’s tricky to disentangle the role played by these different factors because they all co-occur in youth.

To shed new light on the issue, a research team from the University of New Hampshire has pointed their torch elsewhere. They investigated memories originating later in life, and they’ve found that the period between age 40 and 60 contains its own reminiscence bumps, usually formed around major life transitions. This suggests that youth may have the largest trove of memories, but the psychological reasons for this can also play out at other times of life .

The research, published in the Journal of Experimental Psychology: General, asked participants over the age of 65 to recall five memorable experiences they’d had between the ages of 40 and 60 and to identify the most important residential move they had made during this time – 149 participants could provide all this information.

Lead author Karalyn Enz theorised that periods of life involving major transitions – such as moving house – should give rise to a higher density of memories because the transitions give individual events a novel backdrop that means they are laid more firmly in memory, and/or rehearsed more frequently.

Enz’s team calculated that if participants’ memories of life events were distributed across the relevant time period (between the ages 40 to 60), we should expect just 13 per cent of them to fall in the 3-year period around each individual’s residential move, yet significantly more did – on average 1.3 of each participant’s five memorable experiences occurred around their move – 26 per cent, twice what chance would predict.

The researchers dub this effect the "Relocation Bump", a bump that happened without a young brain or during a time of first booze, first jobs, and first loves. Was the effect simply driven by a different significant life event that drove both the move and the other memories? Sixty-five per cent of participants reported this, with the trigger usually retirement or a change of job. But putting these aside, 24 per cent of participants’ recollections still occurred around moving house. Maybe the effect was driven by memories directly related to the moving event itself? In fact with these removed, the relocation bump remained. A move seems to provide the backdrop for other recollections: new places to eat, to sleep, new parks to walk in, weather patterns to feel, somehow making fertile ground for memories to seed.

In my swansong research presentation at the BPS Annual Conference in York in 2007, I suggested that autobiographical memory research benefits when we don’t just approach measurement in terms of chronological years, but "in terms of events, boundaries or stages that were meaningful to the individual." This work shows why that matters. If we think of memories spread over the lifespan as peaks and flatlands, youth is supposed to be the Rocky mountains, and middle adulthood the Kansas Great Plains. But Enz’s team show these plains have their own hills and crags.